Spring-friction draft-gear.



J. H. MITCHELL.

SPRING FRICTION DRAFT GEAR.

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APPLICATION FILED OQT. I8, 1915.

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. UMTED STATES PATENT. OFFICE?.

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f -cirazmivnwronm M vide a"gear of'the typeV 56 `rear end thereof `is 'the position of Toad-ZZ whom z'tmy concem'f i I Be it known; hat I', JOHN R; 'MrrciiiiLm a citizen of` the United States, residing at Chicago; inthe countyof Cook and Stateof Illinois, 'have invented acertain' new` and useful Improvement in'l Spring- Friction Draft-Gears, of. whiclrthe following` is a 1 full,` clear, 'conciseVandr exact description,

reference 'being hadk tothe `accompanying drawings, forming a p art of this specifica# Y tion.

f invention relates to yimprovements in spring friction'draft gears. j

An object offthe'invention is to providea gear for railway draft riggings wherein the action is graduated and has a vspring action only during thev flrSt portions of the buff and draft movements and a friction action during the lattery portions of said movements. Another objectof the'invention'is to pro-- above described whereinnthe Asame spring,

medium when the spring and friction 'actions occur. y

The invention furthermoreconsists in the improvements in theparts and devices and in thenovel combinations of the parts and devices herein shown, described or claimed. A In the drawing forming a part of this specification, Figure 1 is a longitudinal, sectional. view of a draft rigging showing my improvement in connection therewith, the

Vpartsbeing illustrated in normal position. Fig. 2 is a'horizontal, sectional view taken substantially on the line 2-2 of Fig. 1 but `Showing the parts under full buff. VFig. 3

is a view similar to Fig. 2 but illustrating the parts under full draft. And Fig. 4 is a transverse, sectional view taken substantially on the line 4-4 of Fig. 1.

In said drawing, 10-10 denote the center or draft sills to the inner sides of which are secured rear stops 11-11 and front stops 12-'12. The gear proper, as shown, comprises acombined friction cylinder and spring casing 13-14, the spring casing having an integral rear wall 15 adapted to act as a follower under certain conditions, las hereinafter described. Mounted within the friction cylinder 13 is a plurality of friction shoes 16, wedge 18 interposed between Mounted within the spring casing 14, at the a block or follower 19,

Y in the draft'members 10; At the frontend of. thegear, a follower 26 is employedwhich Athe, latter being suitably slotted Atfdreceive the. Vmain Spring, of the gearsl is employed as a'lc'ushioning .the slots 25,' and consequently,

17 and anti-friction rollersV Y' Speeffatiof'ttersBteet; vPatented-pr. 15,1919.` aptueatin iiialoctebriaieis. Vseiaimisaisof vj j i 1 and between the, followei '19d land i'the inner ends of the friction shoes is the main spring 2OA of' the gear vs'flfiioh,S as' shown,- comprises an outer heavy coil andan inner lighter coil; The follower' 19is provided .onvitsforward end with a staple 21`with which is slidably engaged one end of the connecting bolt 22, the opposite end ofl'said bolt extending into the wedgel. /The side walls of the spring casing 1,4, at lthe rear thereof, are provided with elongated key slots 25"l and the: follower 19 is also transversely slottedl to receive the key l24, theends yof the latter beingv slidable forwardly from normalpositi'onfin'slots'25 'o normallyv engagesjthe shoulderson' the front stops 12, and to operatively connect the gear with the Vdraw-bar 27, I employ side 'linksj28,

the' rear key 2i and fhaving'elongated slots 29 at the front ends to receive ,the coupler key BO, 'the A i forwardly sition in slots 31k in the draft members 10.

ends of' the" latter lbeing' slidable and rearwardly from normal po- 80 The operation is `as follows.

It Vwill be noted that in normal position of the parts as shownin Fig. 1, therear wall 15 of thecombined friction shell and spring casing is spaced from the rear stops 11-11. This space may be varied as desired but in actual practice will preferably equal one-half of the total movement of the gear. Upon inward movementof the draw-v bar, rear key 24 will remain stationary, since it is in engagement with the rear ends Vof the follower 19 will remain stationary. The-elongated slots 23 in the spring casing, however, will permit the latter with the friction shoes and wedge to move rearwardly lwithout actuating the friction mechanism but compressing the spring 20 between the shoes and the followerV 19. .his spring actioncontinues until the rear wall 15 engages the stops 11, whereupon the friction cylinder `will remain stationaryr and continued inward movementY of the draw-bar will actuate the friction mechanism against the action of the spring 20. In draft, upon forward movement of the 105 draw-bar the links 28 will be moved forwardly, thus imparting a similarmovement to thek rear key 24 and follower 19. Due the shoes and the shell 13, the latter will not move forwardly 

